Identification of three hydroxysteroid sulfotransferase isoenzymes in the rat liver.
Isolation of several hydroxysteroid sulfotransferase (HS-ST) cDNAs from the rat liver cDNA library has demonstrated the possible expression of these HS-ST isoforms in rat liver. We devised a method to detect unequivocally ST-20 and ST-40 mRNAs by a reverse transcription-polymerase chain reaction, using specific primers. ST-40 mRNA was expressed only in liver, but ST-20 mRNA was present predominantly in the liver and slightly in extrahepatic tissues. On chromatofocusing, expressed ST-20 or ST-40 enzymes were eluted at approx. pH 8.2 and 5.7-4.7 or at pH 6.4-5.4, respectively. Chromatofocusing of adult female rat liver cytosols resolved HS-ST isoenzymes in a broad range of pH, and ST fractions A, B, C, D and E were eluted at approx. pH 8.2, 7.6, 7.5-6.8, 6.2 and 6.1-5.5, respectively. After PAP-agarose affinity column chromatography and SDS-polyacrylamide gel electrophoresis (PAGE), their N-terminal amino acid sequences were determined. ST isoenzymes present in fractions B and E showed identical N-terminal amino acid sequences with those of ST-21 and ST-20, respectively, whereas the ST isoenzymes present in fractions C and D had the same N-terminal amino acid sequence as those of ST-40 (and/or ST-41). The results demonstrated the presence of at least three HS-ST isoenzymes in adult female rat liver.
Takahashi
M
M
Kyoritsu College of Pharmacy, Shibakoen, Tokyo, Japan.
Tamura
H
H
Kondo
S
S
Kobayashi
K
K
Matsui
M
M
D000595:Amino Acid Sequence; D000818:Animals; D002847:Chromatography, Agarose; D003600:Cytosol / Q000201:enzymology; D004591:Electrophoresis, Polyacrylamide Gel; D005260:Female; D007525:Isoelectric Focusing; D007527:Isoenzymes / Q000032:analysis* / Q000096:biosynthesis / Q000302:isolation & purification; D008099:Liver / Q000201:enzymology*; D008297:Male; D008969:Molecular Sequence Data; D016133:Polymerase Chain Reaction; D012333:RNA, Messenger / Q000032:analysis / Q000096:biosynthesis; D051381:Rats; D017208:Rats, Wistar; D015238:Sulfotransferases / Q000032:analysis* / Q000096:biosynthesis / Q000302:isolation & purification
D007527:Isoenzymes; D012333:RNA, Messenger; D015238:Sulfotransferases; C028152:alcohol sulfotransferase